1. Field of the Invention
The present invention generally relates to a method for forming a step channel of a semiconductor device, and more specifically, to a method for forming a step channel of a semiconductor device wherein a spacer is formed on a sidewall of a hard mask layer pattern, and a step channel region having a sloped profile is formed using the hard mask layer pattern and the spacer as an etching mask to prevent damage to a semiconductor substrate during a plasma etching process and improve a sharp profile of the step channel region, thereby improving operating characteristics and yield of the semiconductor device.
2. Description of the Related Art
FIGS. 1a and 1b illustrate a conventional method for forming a step channel of a semiconductor device.
Referring to FIG. 1a, a photoresist film pattern 20 defining a step channel region is formed on a semiconductor substrate 10. The semiconductor substrate 10 is etched via a plasma etching process using the photoresist film pattern 20 as an etching mask.
Referring to FIG. 1b, the photoresist film pattern 20 is removed to form the step channel region. The edge portion of the step channel region which is denoted as ‘A’, is damaged due to the plasma etching process, thereby rendering the upper edge portion and the lower edge portion of the step channel region to have sharp profiles.
In accordance with the above-described conventional method for forming a step channel of a semiconductor device, the damage to the step channel region due to the plasma etching process causes the upper portion and the lower portion thereof to have the sharp profiles, which results in degradation of the operating characteristics and yield of the semiconductor device.